Fluid-driven dental handpiece construction



Aug. 4, 1959 J. A. MAURER 1 2,897,596

FLUID-DRIVEN DENTAL HANDPIECE CONSTRUCTION Filed Jan. 3, 1958 IN V ENTOR.

JohnAMwwrer HTTOHVEYS "mired St FLUID-DRIVEN DENTAL HANDPIECECONSTRUCTION Application January 3, 1958, Serial No. 707,059

8 Claims. (CI. 3227) My invention relates generally to improvements influid-driven dental handpiece construction and more specifically to themeans for mounting the fluid-drlven turbine contained in such ahandpiece. Furthermore the present invention is an improvement on theconstruction disclosed in a copending application Serial No. 618,325,filed October 25, 1956 and of which I am a coinventor.

The fluid-driven dental handpiece construction (118-- closed in theabove referred to copending application includes an elongated handlehaving a fluid supply and exhaust portion formed at one end thereof anda turbine or rotor casing formed at the other end, with this turbine orrotor having burr holding means directly connected therethrough androtatable therewith for mounting and rotating a conventional dental burrtube used for drilling teeth. Further this prior handpiece includesconduit means extending from the fluid supply and exhaust sectionlengthwise through the elongated handle and being connected to a nozzleor other means for directing a jet or stream of the fluid, such as air,toward the turbine. In this manner the turbine is rotated, and thisfluid is then exhausted from the turbine around the nozzle andlengthwise back through the handle around the fluid supply conduit.

After the fluid reaches the fluid supply and exhaust section of thehandpiece, after traveling lengthwise through the handle from theturbine, when the fluid used is air, it can be exhausted into theatmosphere. As disclosed in this copending application, in order tominimize the noise caused by this fluid exhausting into the atmosphere,and also to aid in mufliling the noise of the fluid striking the turbineand exhausting from the turbine, it was necessary to provide a rathercomplicated mufller construction at the supply and exhaust section ofthe handpiece, which mufiler construction is not only somewhatcumbersome but is also rather expensive to manufacture.

Without this mufller construction, however, it has been found that thenoise created by this fluid exhausting from the handpiece andparticularly the noise created by the fluid circulating in and aroundthe turbine is extremely objectionable and in fact prohibitive, bothfrom the standpoint of the dentist using the handpiece and the patientwhose teeth are being drilled. Also a great amount of noise is createdby the bearings which mount the turbine for rotation, and all of thesefactors are even more apparent when it is considered that this turbineis capable of rotating at speeds in the order of between 100,000 and200,000 revolutions per minute.

According to the principles of the present invention, however, it hasbeen found that the rather complicated muffler construction used at thesupply and exhaust section of the handpiece can be eliminated merely bymounting the turbine and turbine bearings within the turbine casing byspecial insulating or muifling means, with the shape and particularrelationship of this muflling means es Patent to the turbine being ofthe utmost importance. Furthermore it has been found, with the specialmuifling means being provided for mounting the turbine and turbinebearings and thereby substantially eliminating any great amount of noisebeing created at the turbine end of the handpiece by the bearingsrotating at these extremely high operating speeds and the fluid strikingand circulating around the turbine, that the noise created by the fluidexhausting at the supply and exhaust section of the handpiece is notexcessive nor objectionable.

It is, therefore, a general object of the present invention to provide afluid driven dental handpiece construction in which the noise ofoperation thereof is greatly reduced and is not objectionable to thedentist using the handpiece or his patients.

It is a primary object of the present invention to provide a fluiddriven dental handpiece construction in which novel mounting means isused for mounting the fluid turbine and the bearings thereof in theturbine casing to thereby decrease the noise of operation of theturbine.

It is also an object of the present invention to provide a fluid drivendental handpiece construction in which the novel means for mounting thefluid turbine and bearings thereof in the turbine casing not onlymuflles the noise created by these bearings but also serves as a mufliefor fluid such as air being deflected from the turbine or escaping fromthe turbine during the rotation thereof which would normally strike theturbine casing.

Finally it is an object of the present invention to provide a fluiddriven dental handpiece construction which satisfies all of the aboveobjects in a simple and eflicient manner and reduces the manufacturingcost thereof below that heretofore possible.

These and other objects are accomplished by the parts, constructions,arrangements, combinations and subcombinations comprising the presentinvention, the nature of which is set forth in the following generalstatement, a preferred embodiment of which-illustrative of the best modein which applicant has contemplated applying the principles-is set forthin the following description andillustrated in the accompanyingdrawings, and which is particularly and distinctly pointed out and setforth in the appended claims forming a part hereof.

In general terms the improved fluid driven dental handpiece constructioncomprising the present invention may be stated as including an elongatedhandle member having a turbine casing mounted at one end thereof, withthis turbine casing having a generally cylindrical bore formed thereinfor reception and mounting of a fluid turbine assembly. The fluidturbine assembly is comprised of a fluid driven turbine preferablymounted for rotation by bearing means at either end thereof.

Further according to the principles of the present invention, theturbine assembly also includes a plastic sleeve surrounding the outercircular peripheries of the turbine and bearing means with this plasticsleeve extending completely across the outer peripheries of the turbineand bearing means and being free of openings at said outer peripheriesexcept at the point of connection between the turbine casing and theelongated handle of the handpiece. Finally the construction includesmeans for supplying fluid to the turbine for rotating the same andexhausting fluid therefrom, and also means operably connected to theturbine for mounting a dental burr tube rotated by the turbine.

By way of example, an embodiment of the fluid driven dental handpiececonstruction of the present invention is illustrated in the accompanyingdrawings forming a part hereof, wherein like numerals indicate similarparts throughout the several views, and in which:

Fig. 1 is a fragmentary vertical section, part in eleva- 3 tion, lookingin the direction of the arrows 11 in Fig.

Fig. 2 a fragmentary sectional View, part in elevation, looking in thedirection of the arrows22 in Fig. 1;

Fig. 3asectional view, part in elevation, looking inthedirection of thearrows 3'3 in Fig. l; and

Fig. 4 a sectional view, part in elevation, looking in the direction ofthe arrows 44 in Fig. 1- with the turbine assembly and turbine casingcaps removed.

The fluid driven dental handpiece construction comprising the presentinvention in general construction is preferably similar to theconstruction disclosed in the copending applicaiton Serial No; 618,325referred toabove with addition of the novel construction as hereindisclosed and claimed; The main exceptions to this are that. the mufflerconstruction at the fluid supply and ex haust section of this priorconstruction iseliminated and a conventional coolant attachment isprovided in the present construction mounted on'the outer periphery ofthe handle as will be hereinafter described in detail; Other slightdifierences will be apparent from the following description.

Referring to the drawings and particularly Fig. 1, the fluid drivendental handpiece construction of the present invention includes a handlemember, generally indicated at 10, having a turbine casing, generallyindicated at' 11, attached thereto, with this turbine casing enclosingand mounting a turbine assembly, generally indicated at 12. Stillfurther, the construction preferably includes a conventional coolantspray attachment, generally indicated at 1-3, and a fluidsupply andexhaust section (not shown) at the end of the handle member 10 oppositefrom the turbine casing 11.

The handle member 10 is preferably cylindrical and hollow and has. aresilient material fluid supply tube 14 extending lengthwisetherethrough from the supply and exhaust section to the nipple 15 of thefluid directing means 16, which directing means is also enclosed by thehandle. member 16 adjacent the turbine casing 11. The fluid directingmeans 16 is also preferably generally cylindrical and is preferablyreceived in handle member- 10 in proper position by a press fit.

Further this directing means includes a' nozzle portion 17 for directingfluid. in a specific manner and at a specific location. toward theturbine assembly 12 in the turbine casing 11, and also this directingmeans is provided with a cutout portion extending the complete lengthalong one side thereof. This cutout portion forms, with the'handlemember 10, an exhaust conduit 18 forreceiving fluid exhausted from theturbine assembly 12 and for transmitting this exhaust fluid back throughthe handle member 10 and ultimately around the fluid supply tube 14- tothe supply and exhaust section. Finally the handle member 10 is providedwith the connection assembly, generally indicated at 19, intermediatethe ends thereof, which may be selectively released for changing theposition of the turbine casing 11 with reference to the main, portion ofthis handle member.

It is also preferred to provide the conventional coolant sprayattachment 13 mounted on the handle member 18' by the clip 2%. Thisattachment includes the coolant supply tube 21 connected to the coolantdirecting nozzle 22, as shown.

The turbine assembly generally indicated at 12 includes the turbine 23,the bearings 24 and 25 and, according to the principles of the presentinvention, the muffle sleeve 26. Further turbine 23. may be formedintegral with the burr holder, generally indicated at 27, which holderincludes the collet 28. Burr holder 27 may also be formed centrallythrough turbine 23 and bearings 24 and 25, as shown, and serves thepurpose of holding the dental burr so that holder 27 and the burr may berotated bythe turbine 23.

Turbine 23 may be provided with impelling means such as the turbinebuckets 29'spaced around he outer peripheries thereof in radialalignment with the nozzle portion 17 of the fluid directing means 16.Further turbine 23 is rotatably mounted within the turbine casing 11 bymeans of the bearings 24 and 25 with these bearings being mounted atopposite ends of the turbines surrounding portions thereof andaxiallyoutward of the turbine buckets 29. 4

Bearings 24' and 25 are in turn mounted in the 'bore 30 of the turbinecasing 11 by means of the muffle sleeve 26 with this sleeve surroundingthe bearings and also surrounding the outer periphery of the turbine 23except at the point of connection of the turbine casing 11' to thehandle member 10. Thus, as shown, bearings 24 and 25' are pressed overthe end portions of'the turbine 23 and this assembly ofturbineandbearings is encased with the muflie sleeve 26. Still further,this entire assembly is mounted in the turbine casing 11 by a press fit.

It is important to point out that, with this construction of turbine 23,bearings 24 and 25 and muifle sleeve 26, the only mounting connectionbetween the bearings and the turbine, casing 11 is through the thicknessof the muflle sleeve. Furthermore it is important to point out that themuflie sleeve 26 extends completely between bearings 24 and 25, aroundthe outer periphery of the turbine 23, except at the point where theturbine casing 11 is connected to the handle 10, atwhich point themutfle sleeve must be removed in order to permit the turbine 23 toreceive fluid from the nozzle portion 17 of the fluid directing means 16and to permit the turbine to exhaust fluid therefrom into the exhaustconduit 18.

Finally the turbine casing 11 is provided at its upper end, adjacent theupper end of the muflie sleeve 26, with cap 31 threadably receivedtherein closing this upper end; Also the lower end is enclosed by a cap32 received bya press fit in this lower end abutting the lower end ofthe muffle sleeve 26 and surrounding the lowerend of the burr holder 27.

In order for the muflle sleeve 26 to perform its function of reducingthe noise caused by the rotation of turbine 23 and bearings 24 and 25,and the noise created by the fluid striking the turbine and deflectingtherefrom toward the turbine casing 11, it is necessary that this sleevehave a certain degree of resiliency. Further, in order to retain theturbine and bearings properly mounted within the turbine casing,it isalso necessary that this sleeve be of suflicient body to retain thepress fit between the bearings 24 and 25 and the turbine casing 11.

One type of material that has been found particularly effective for thispurpose is the class of materials known as memory plastics. The mosteffective of these materials wh-ich has thus far been found is onecommercially known as Teflon which is apolymerized tetrafluoroethylenecomposition, and it is believed that certain other of the memoryplastics may be just as effective.

Thus this resilient plastic muffle sleeve insulates the bearings 24 and25 from the turbine casing 11 thereby preventing any vibrations frompassing between these hearings and the turbine casing. Further, and justas important, is the fact that the muflie sleeve 26 also extends betweenthe bearings and around the outer periphery of the turbine 23 so thatany fluid being deflected from this turbine, which is rotating at anextremely high rate of speed, does not strike the surface within theturbine casing bore 30, but rather strikes the muffle sleeve 26 which.again insulates and prevents any noisev from being created .by thisdeflected fluid.

Thus, according to the principles of the present invention, a fluiddriven dental handpiece construction is provided in which the noisenormally created by the bearings mounting the turbine and also the noisenormally created by the fluid striking the turbine and being deflectedtherefrom is eifectively reduced, with this being accomplished' in asimple and efficient manner at a minimum expense and without requiringany bulky attachments to the handpiece.

In the foregoing description, certain terms have been used for brevity,clearness and understanding, but no unnecessary limitations are to beimplied therefrom, because such words are used for descriptive purposesherein, and are intended to be broadly construed.

Moreover, the embodiment of the improved construction illustrated anddescribed herein is by way of example, and the scope of the presentinvention is not limited to the exact details of the construction shown.

Having now described the invention, the construction, operation and useof a preferred embodiment thereof, and the advantageous, new and usefulresults obtained thereby; the new and useful construction and reasonablemechanical equivalents thereof obvious to those skilled in the art areset forth in the appended claims.

I claim:

1. Fluid-driven dental handpiece construction including an elongatedhandle having an end portion, a turbine casing connected to said handleend portion, plastic sleeve means mounted coaxially in said turbinecasing, a turbine having a longitudinally extending peripheral surfacehaving impelling means formed therein, bearing means rotatably mountingthe turbine in the plastic sleeve means and coaxially with said sleevemeans, said sleeve means surrounding said bearing means between saidbearing means and the turbine casing and extending over the peripheralsurface of the turbine between said surface and said turbine casing forinsulating the bearing means from said casing and deflecting fluidescaping from the turbine impelling means which would normally strikethe casing, means for supplying fluid to the turbine for rotating saidturbine, means for exhausting fluid from the turbine, and means operablyconnected to the turbine for holding a dental burr.

2. Fluid-driven dental handpiece construction as defined in claim 1 inwhich the turbine has end portions at opposite ends of said peripheralsurface; in which the bearing means includes a bearing mounted at eachend portion of the turbine; in which the turbine peripheral surface andimpelling means is positioned between said bearings; and in which theplastic sleeve means surrounds each of said bearings between thebearings and the turbine casing and extends longitudinally between saidbearings over the turbine peripheral surface and impelling means.

3. Fluid-driven dental handpiece construction as defined in claim 1 inwhich the handle has a longitudinal axis; in which the turbine casinghas a longitudinal axis; in which the turbine casing is connected to thehandle with the longitudinal axes of said casing and handle extendingsubstantially perpendicularly to each other; in which the plastic sleevemeans has an opening formed therein at said connection of the handle andcasing; in which the means for supplying fluid to the turbine and themeans for exhausting fluid from the turbine extend 6 through the handleand communicate with the turbine from said handle into the turbinecasing through the plastic sleeve means opening; and in which the meansfor holding a dental burr is connected to the turbine substantiallyaligned with said turbine casing longitudinal axis.

4. Fluid-driven dental handpiece construction as delined in claim 1 inwhich the plastic sleeve means is formed from a memory plastic.

5. Fluid-driven dental handpiece construction as defined in claim 4 inwhich the memory plastic is a polymerized tetrafluoroethylenecomposition.

6. Fluid-driven dental handpiece construction including an elongatedhandle having an end portion and a longitudinal axis, a turbine casinghaving a longitudinal axis and being connected to said handle endportion with the longitudinal axes of said casing and handle extendingsubstantially perpendicularly to each other, plastic sleeve meansmounted coaxially in said turbine casing, said plastic sleeve meanshaving an opening formed therein at said connection of the casing andhandle, a turbine having a longitudinally extending peripheral surfacehaving impelling means formed therein, the turbine having end portionsat opposite ends of said peripheral surface, a bearing mounted at eachend portion of the turbine and rotatably mounting the turbine in theplastic sleeve means and coaxially with said sleeve means, the plasticsleeve means surrounding each of said bearings between the bearings andthe turbine casing and extending longitudinally between said bearingsover the turbine peripheral surface and impelling means for insulatingthe bearings from said casing and deflecting fluid escaping from theturbine impelling means which would normally strike the casing, meansextending through the handle and communicating with the turbine fromsaid handle into the turbine casing through the plastic sleeve meansopening for supplying fluid to the turbine to rotate said turbine, meansextending through the handle and communicating with the turbine fromsaid handle into the turbine casing through the plastic sleeve meansopening for exhausting fluid from said turbine, and means connected tothe turbine substantially aligned with said turbine casing longitudinalaxis for holding a dental burr.

'7. Fluid-driven dental handpiece construction as defined in claim 6 inwhich the plastic sleeve means is formed from memory plastic.

8. Fluid-driven dental handpiece construction as defined in claim 7 inwhich the memory plastic is a polymerized tetrafluoroethylenecomposition.

References Cited in the file of this patent UNITED STATES PATENTS2,251,057 Iseman July 29, 1941

